Client computing devices may request files, such as network pages, from one or more servers over a network. As one example, a client computing device may receive a page from a server, such as a HyperText Markup Language (“HTML”) page, that include references to one or more image files or other content to be presented for display. The client computing device may then request the one or more image files from the appropriate server and present the image files for display, along with other content of the page. A typical user interface presented by a browser or similar software installed on a client computing device for displaying a network page may include selectable links or other selectable options that a user may select via a cursor or other navigational mechanism in order to request a new network page from a server. For example, a user interface displaying a network page that lists a number of products available for purchase may enable a user to select identification information for one of the products in order to request a new network page that includes additional information regarding the selected product. Some browsers, such as those executed on mobile computing devices, enable a user to zoom in and zoom out of content presented by a browser executed by the computing device.